[llvm-branch-commits] [libcxx] [libc++][modules] Adds module testing. (PR #76246)

[Louis Dionne via llvm-branch-commits]

================
@@ -132,13 +154,62 @@ def parseScript(test, preamble):
     script += scriptInTest
 
     # Add compile flags specified with ADDITIONAL_COMPILE_FLAGS.
+    # Modules need to be build with the same compilation flags as the
+    # test. So add these flags before adding the modules.
     substitutions = [
         (s, x + " " + " ".join(additionalCompileFlags))
         if s == "%{compile_flags}"
         else (s, x)
         for (s, x) in substitutions
     ]
 
+    if modules:
+        _validateModuleDependencies(modules)
+
+        # This flag is needed for both modules.
+        #moduleCompileFlags.append("-fprebuilt-module-path=%T")
+
+        # The moduleCompileFlags are added to the %{compile_flags}, but
+        # the modules need should be built without these flags. So
+        # expand the compile_flags and add the expanded value to the
+        # build script.
----------------
ldionne wrote:

```suggestion
        # The moduleCompileFlags are added to the %{compile_flags}, but
        # the modules need to be built without these flags. So expand the
        # %{compile_flags} eagerly and hardcode them in the build script.
```

https://github.com/llvm/llvm-project/pull/76246